1. Field of the Invention
The invention relates generally to vascular access devices such as catheter assemblies. The invention is particularly directed to a catheterization assembly designed to reduce the risk of infection, transmission of bloodborne pathogens, loss of blood, and development of embolisms in a patient. The catheterization assembly incorporates a catheter hub that has multiple access ports for allowing air to exit the catheterization assembly, providing fluid communication between a valve and a catheter, and enabling insertion and removal of a catheter introducer without leakage of body fluids from the catheterization assembly.
2. Description of the Related Art
In current medical practice, it is often necessary to have access to the venous system of a patient. For example, it is a common procedure to obtain diagnostic information about the heart or its vessels by inserting a tube (a “catheter”) into a vein of the patient and withdrawing blood. Oftentimes, catheterization is necessary to deliver fluids such as medications into the patient's venous system. Additionally, it may be necessary to aspirate fluids from the catheter site to evaluate blood profiles, perform diagnostic assays, etc.
Typically catheterization is conducted by inserting a needle, or other introducer, directly into a patient's vein and pushing or threading a catheter through the entry site created by the needle. Conventional catheterization practice has been to introduce the catheter into the patient's vein and then to attach a secondary component, such as an injection port with a sealed septum, to the catheter to prevent blood leakage, minimize catheter clotting, and to facilitate the introduction of medications or aspirate fluids. In this case the introduction or aspiration of fluids is accomplished by utilizing a needle to penetrate the septum thereby accessing the patient's vasculature via the catheter. The needle is generally inserted into a sealed entry port.
Since the early 1990's, infection by bloodborne pathogens has become a serious concern to health care workers and patients alike. HIV/AIDS and various forms of hepatitis have caused a dramatic shift in the way medical devices are constructed. The elimination of needle sticks and blood contact have been the primary design changes. However, many devices currently marketed as “safety” devices fall short of the goal of preventing the transmission of bloodborne pathogens.
Any device connected to the patient's bloodstream should not have an exposed fluid reservoir due to the potential for bacterial infection from contact with a tainted object. If the fluid reservoir or cavity is not cleaned, then there is a potential for developing bacteria in the fluid reservoir. The bacteria could be introduced into a patient's bloodstream when the device is subsequently used to administer new medications to or aspirate fluids from the patient. Additionally, there is a risk of blood coagulating in the catheter and possibly in the injection apparatus; hence, these components must be frequently replaced thereby creating possible medical complications as well as additional discomfort, pain, and cost to the patient.
Turning in particular to the case of catheters, certain catheters such as Peripherally Inserted Central catheters (“PICCs”), Midline (“Mid”) catheters, and Peripheral catheters can remain in a patient for hours or in some cases as long as 180 days. During the course of treatment with a catheter, a patient's venous system may be accessed a number of times to either remove or introduce fluids.
The traditional PICC, Mid, or peripheral catheter is constructed of a length of tubing terminating at the proximal end with a female luer hub (a “catheter hub”). The primary difference between these three catheters is the length of the tubing. The rationale for different lengths is based on the type and duration of the therapy a patient is to receive.
The insertion of these catheters into a patient's venous system can differ procedurally. The peripheral catheter, being the shortest of the three types and measuring about 3.5″ in length, is often inserted into a patient's vein through the use of a needle disposed within the catheter tube. These types of catheters are frequently referred to as “over-the-needle catheters.” The peripheral catheter is percutaneously inserted into a peripheral vein and terminates in the same peripheral vein. After insertion, the needle is removed, leaving the catheter in the vein. Often, blood will flow out of the back of the luer hub and expose the health care worker to blood contact. Usually, a second component commonly referred to as a “J-loop” is attached to the catheter hub.
A J-loop is a tube approximately 6″ in length and is often configured with an injection cap, luer fitting, or needle free valve at its proximal end. Typically, the J-loop is also configured with a male luer fitting at its distal end for attachment to other devices. The J-loop primarily functions to allow handling of injection ports or fluid flow regulating devices away from the point of insertion of the catheter into the patient. Without the use of a J-loop, manipulation of an injection cap, for example, connected directly to the catheter hub would likely result in the inadvertent dislodging of the catheter from the patient. When the J-loop is not supplied with some terminal connector the health care worker must supply one in order to prevent leakage of bodily fluids from the J-loop, or to provide an access port to the catheter via the J-loop.
The PICC and Mid are inserted in a similar fashion. Typically, an introducer is placed into the vein first. The introducer is a thin splittable tube whose internal diameter (ID) is closely matched to the outside diameter (OD) of the internally disposed needle in much the same way as described with reference to the peripheral catheter. Once the introducer has been placed in the vein, the needle is removed and again, blood can be seen to come out of the proximal end of the introducer. The introducer will remain in place and acts as a conduit for threading the PICC or Mid catheter into the patient's vein. Once the PICC or Mid catheter is in the vein, the introducer is removed, and blood can often escape from the hub of the catheter.
Thus, to date, there is an absence of safety devices on the market which reduce or prevent the risk of exposure to bloodborne pathogens to health care workers during and after catheter insertion.
It has also been recognized that known catheterization devices contribute to the incidence of transmission of nosocomial infections to a patient undergoing catheterization. Since 1970, the Center for Disease Control (CDC)'s National Nosocomial Infection Surveillance System (NNIS) has been collecting data on the incidence and etiologies of hospital acquired infections. The majority of hospital-acquired bloodstream infections are associated with the use of a catheter, particularly central venous catheters.
Today, catheter maintenance requires many manipulations of the catheter. For example, every three days, injection caps, valves, and tubing must be replaced. In so doing, the health care worker can inadvertently expose the patient to nosocomial infections caused by bacteria, viruses, and/or fungi. Each and every manipulation that opens the catheter's closed system exposing it to airborne bacteria and touch contamination is a potential source of danger to the patient. Types of organisms that most commonly cause hospital-acquired bloodstream infections include, Staphylocooccus aureus, Candida spp., Escherichia coli, Pseudomonas aeruginosa, Acinetobacter calcoaceticus, and Klebsiella pneumoniae. These microorganisms can infect the patient's bloodstream and, in extreme cases, sepsis and death can result.
The known catheterization devices typically lack features to reduce the risk to the patient of an air embolism. The insertion of a central catheter exposes a patient to the possibility of “sucking” air through the catheter into the patient's bloodstream. This risk can result in death or serious injury to the patient.
Moreover, the known catheterization assemblies often increase the cost of medical care. In today's market, as stated earlier, PICCs can often be in a patient for periods of time up to 180 days. Valves are attached to these catheters to allow for the introduction of drugs, diagnostic agents, etc. Because the valves are detachable, the Center for Disease Control (“CDC”) dictates that these valves must be replaced every 72 hours. Valves typically cost approximately $1.50/each (USD). Over a 180 day period, on average, sixty valves must be replaced at a cost of nearly $90.00 (USD). Accordingly, there is a need for catheterization assemblies having valves which prevent blood backflow and which are not required to be replaced periodically to reduce health care costs.
Consequently, there is a constant need in the relevant technology for improved safety devices which prevent or reduce the risk to the patient of transmission of bloodborne pathogens, loss blood, infection, or air embolism in the course of insertion and use of catheter devices. Additionally, affordable safety devices would be a great benefit to both the patient and medical community.